312 STUDIES ON FERMENTATION. 



question of the animal or vegetable nature of the ferment, of 

 the organized being, have upon the investigation of these two 

 problems ? In studying butyric fermentation, for example, ■v\e 

 endeavoured to establish these two fundamental points: — 1. 

 The butyric ferment is a vibrio. 2. This vibrio may dispeme with 

 air in its life, and, as a matter of fact, does dispense with it in the 

 act of producing butyric fermentation. We did not consider it 

 at all necessary to pronounce any opinion as to the animal or 

 vegetable nature of this organism, and, even up to the present 

 moment, the idea that vibrio is an animal and not a plant is, 

 in our minds, a matter of sentiment rather than of conviction. 



M. Robin, however, would have no difficult}'- in determining 

 the limits of the two kingdoms. According to him, " every 

 variety of cellulose is, we may say, insoluble in ammonia, as 

 also are the reproductive elements of plants, whether male or 

 female. Whatever phase of evolution the elements which 

 reproduce a new individual may have reached, treatment with 

 this reagent, either cold or raised to boiling, leaves them abso- 

 lutely intact under the eyes of the observer, except that their 

 contents, from being partially dissolved, become more trans- 

 parent. Every vegetable, whether microscopic or not, every 

 mycelium, and every spore thus preserves in its entirety its 

 special characteristics of form, volume, and structural arrange- 

 ments ; whilst in the case of microscopic animals, or the ova and 

 microscopic embryos of different members of the animal king- 

 dom, the very opposite is the case." 



We should be glad to learn that the employment of a 

 drop of ammonia would enable us to pronounce an opinion, 

 with this degree of confidence, on the nature of the lowest 

 microscopic beings ; but is M. Robin absolutely correct in his 

 assumptions ? That gentleman himself remarks that sperma- 

 tozoa, which belong to animal organisms, are insoluble in 

 ammonia, the effect of which is merely to make them paler. 

 If a difference of action in certain reagents, in ammonia, for 

 example, were sufficient to determine the limits of the animal 

 and vegetable kingdoms, might we not argue that there must 



